[syslinux] Question about syslinux EFI alpha version

Matt Fleming matt at console-pimps.org
Thu May 9 05:51:45 PDT 2013

On 05/09/2013 12:40 PM, Klaus Knopper wrote:
> My current findings:
> 1. syslinux.efi looks for and loads ldlinux.sys in the current directory
> (which is in fact ldlinux.c32 and should be changed to something 32- or
> 64-bit specific so multiplatform boot is supported).

ldlinux.sys and ldlinux.c32 are not the same file. ldlinux.sys contains
the ADV data and ldlinux.c32 is a module that contains all the
non-essential code for Syslinux to function in its most primitive form.

> 2. My kernel images are not loaded since "format 0x20b not supported".
> (same kernel works with grub.efi and elilo.efi)

Yeah, version 0x20b of the kernel introduced the EFI handover protocol.
We actually don't need to be so strict with which kernel versions we
boot. I'll look at relaxing this constraint. Which Linux kernel version
are you booting?

> 3. Config files of syslinux version 4 are found and used in
> boot/syslinux, however, the boot picture does not display.

Is this a lss16 image? I'm currently working on fixing this for the 5.x
branch, and the fix will make its way into 6.x.

> My wishlist:
> 1. Possibility to generate syslinux.efi as a single binary with no
> dynamic loading of ldlinux.sys or *.c32 required. This would also make
> multiplatform support easier, renaming syslinux.efi/64bit to
> bootx64.efi, and syslinux.efi/32bit to bootx32.efi.

Yeah, that could be a good idea. It would save us from having to invent
a scheme to ensure we load the correct ldlinux.c32 depending on whether
we're booting 32-bit or 64-bit.

> 2. Support of my EFIstub-enabled bzImage format (maybe xz-compression
> type is to blame?)

EFI stub enabled kernels are definitely supported. I'm guessing it's
that you're running into the above message about the header version not
being supported?

Matt Fleming, Intel Open Source Technology Center

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